I've seen it asked many times: "Can I change film simulations without the raw file?" The answer would always be "no, shoot raw like a real man".

With Fujify's color engine "knowing" how to recreate film simulations, it also "knows" how to undo them - directly on the JPEG, without the raw file. The same applies for video footage with baked in film simulations.

You can find a few examples below.

To make it clear that they're JPEGs and not raws with film simulations applied, there's also a text layer on top which changes color once the film simulation is changed.